title: Exercise-induced bronchoconstriction as an expression of bronchial hyperreactivity: a study of its mechanisms in children.
abstract: The mechanism of exercise-induced bronchoconstriction (EIB) was studied by observing the protective effects of several aerosol agents in a double-blind, randomised trial. Exercise-induced bronchoconstriction was not affected by placebo, but was reduced by each agent used (p less than 0.001). Blocking the parasympathetic system had the weakest effect, while beta 2 adrenergic stimulation produced the strongest effect which was significantly different from the parasympatholytic (p less than 0.02). The effect of the mast cell stabilizer, sodium cromoglycate (SCG) was found to be intermediate. However in some patients SCG had a stronger effect than the beta 2 adrenergic agonist. A relationship was found between EIB and bronchial hyperreactivity induced by histamine (p less than 0.05).
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000517:prevention & control*; D001250:Asthma, Exercise-Induced / Q000503:physiopathology / Q000517:prevention & control*; D002648:Child; D002986:Clinical Trials as Topic; D004205:Cromolyn Sodium / Q000627:therapeutic use*; D004311:Double-Blind Method; D004983:Ethanolamines / Q000627:therapeutic use*; D005260:Female; D005280:Fenoterol / Q000627:therapeutic use*; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D012602:Scopolamine Derivatives / Q000627:therapeutic use*
chemical_list: D004983:Ethanolamines; D012602:Scopolamine Derivatives; D005280:Fenoterol; C017590:oxitropium; D004205:Cromolyn Sodium